FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
“AGRICULTURAL HARVESTER HAVING A FOUR WHEEL DRIVE SYSTEM”
CNH Industrial (India) Pvt. Ltd. of the address: B1-207, Boomerang, Chandivali Farm Road, Near Chandivali Studio, Andheri (East) Mumbai – 400 072, India.
The following specification particularly describes the invention and the manner in which it is to be performed:

AGRICULTURAL HARVESTER HAVING A FOUR WHEEL
DRIVE SYSTEM
BACKGROUND
[0001] The present disclosure relates generally to an agricultural harvester having a four wheel drive system.
[0002] An agricultural harvester may be used to harvest agricultural crops, such as corn, wheat, flax, or other crops. Generally, components (e.g., drums, spindles, blades, etc.) within a header of the agricultural harvester engage and collect the agricultural crops. The agricultural harvester then conveys the agricultural crops to a processing device configured to separate the agricultural crops into agricultural products and residue. Certain harvesters include an auger assembly positioned beneath a frame of the agricultural harvester and configured to receive the agricultural products. The auger assembly conveys the agricultural products to an elevator, which then conveys the agricultural products to an internal storage compartment.
[0003] Agricultural harvesters may be operated in a variety of soil conditions. For example, an agricultural harvester may be driven through a field having soft soil (e.g., due to a high moisture content within the soil). In certain soft soil conditions, wheels and/or tracks of the tractor may slip relative to the soil surface. Accordingly, certain agricultural harvesters utilize a four wheel drive system to enhance traction. Typical four wheel drive systems include a shaft extending between a front axle (e.g., drive axle) and a rear axle (e.g., driven axle). Because the auger assembly is positioned beneath the frame of the agricultural harvester, the shaft is typically positioned below the auger assembly. Unfortunately, positioning the shaft below the auger assembly reduces the ground clearance of the agricultural harvester.
BRIEF DESCRIPTION
[0004] In certain embodiments, an agricultural harvester includes an auger assembly configured to move agricultural product toward an elevator. The

agricultural harvester also includes a drive shaft assembly. A portion of the drive shaft assembly is positioned laterally outward of the auger assembly, and the portion of the drive shaft assembly extends within a vertical extent and a longitudinal extent of the auger assembly, such that the portion of the drive shaft assembly and the auger assembly overlap one another along a vertical axis and along a longitudinal axis of the agricultural harvester. In addition, the agricultural harvester includes an axle assembly having an input. The drive shaft assembly is coupled to the input of the axle assembly, and the drive shaft assembly is configured to transfer rotational energy.
DRAWINGS
[0005] These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
[0006] FIG. 1 is a side view of an embodiment of an agricultural harvester having a four wheel drive system;
[0007] FIG. 2A is a perspective view of an embodiment of a four wheel drive system that may be employed within the agricultural harvester of FIG. 1;
[0008] FIG. 2B is a right side view of the four wheel drive system of FIG. 2A;
[0009] FIG. 2C is a top view of the four wheel drive system of FIG. 2A;
[0010] FIG. 2D is a back view of a portion of the four wheel drive system of FIG. 2A; and
[0011] FIG. 3 is a perspective view of another embodiment of a four wheel drive system that may be employed within the agricultural harvester of FIG. 1.

DETAILED DESCRIPTION
[0012] One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
[0013] When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Any examples of operating parameters and/or environmental conditions are not exclusive of other parameters/conditions of the disclosed embodiments.
[0014] Turning to the drawings, FIG. 1 is a side view of an embodiment of an agricultural harvester 100 having a four wheel drive system. The agricultural harvester 100 is configured to travel along a surface 10 of an agricultural field 12 in a direction of travel 14. As the agricultural harvester 100 travels through the agricultural field 12, a header 102 disposed at the front of the agricultural harvester 100 collects agricultural crops. The agricultural harvester 100 processes the agricultural crops to separate a portion that is collected (e.g., agricultural product) from a portion that is returned to the agricultural field (e.g., residue). The portion that is returned to the agricultural field (e.g., residue) is discharged by the agricultural harvester 100 at a residue spreader 104. The crop residue that is returned to the

agricultural field covers the agricultural field and may be used to return nutrients to the agricultural field 12.
[0015] The portion of the agricultural crops that is collected (e.g., the agricultural product) is conveyed via an airflow (e.g., provided by a blower) to an auger assembly positioned below a frame of the agricultural harvester 100. The auger assembly moves the agricultural product laterally outward to an elevator, and the elevator conveys the agricultural product upwardly to an internal storage compartment positioned above the frame of the agricultural harvester 100. The agricultural product may be stored within the internal storage compartment as the agricultural harvester 100 traverses the agricultural field 12. The agricultural product may then be transferred to an external storage compartment for transport or storage. In certain embodiments, the agricultural harvester may transfer the agricultural product from the internal storage compartment to a mobile external storage compartment (e.g., towed by a work vehicle) while the agricultural harvester is harvesting agricultural crops (e.g., a process that may be known as “unloading on the go”).
[0016] As discussed in detail below, the agricultural harvester 100 includes a four wheel drive system configured to enhance traction of the agricultural harvester in soft soil conditions (e.g., while the agricultural harvester is operating within soil having a high moisture content). In certain embodiments, the four wheel drive system may be selectively engaged and disengaged based on soil conditions (e.g., disengaged for firmer soil conditions and engaged for softer soil conditions). The four wheel drive system includes a drive shaft assembly, in which a portion of the drive shaft assembly that longitudinally overlaps the auger assembly is positioned laterally outward of the auger assembly. In certain embodiments, the portion of the drive shaft assembly may also be positioned beneath or laterally inward of the elevator. The four wheel drive system also includes an axle assembly (e.g., rear axle assembly) configured to support a left wheel on a left side of the axle assembly and to support a right wheel on a right side of the axle assembly. The axle assembly has an input (e.g., laterally offset from a midpoint between the left wheel and the right wheel). The drive shaft assembly is coupled to the input of the axle assembly and configured to transfer rotational energy to the axle assembly. Because the portion of the drive shaft assembly is positioned

laterally outward of the auger assembly, the distance between the surface 10 of the agricultural field 12 and the drive shaft assembly may be increased (e.g., as compared to a drive shaft assembly having a portion that extends below the auger assembly). As a result, the ground clearance of the agricultural harvester 100 may be enhanced, thereby enabling the agricultural harvester to traverse larger obstacles in the field.
[0017] FIG. 2A is a perspective view of an embodiment of a four wheel drive system 200 that may be employed within the agricultural harvester 100 of FIG. 1. In the illustrated embodiment, the agricultural harvester 100 includes a frame 106, a front axle assembly 108, and a rear axle assembly 110. As illustrated, the front axle assembly 108 is positioned forward of the rear axle assembly 110 along a longitudinal axis 16 relative to the direction of travel 14. The frame 106 is coupled to the front axle assembly 108 and to the rear axle assembly 110, such that the front and rear axle assemblies support the frame 106. Each axle assembly may be coupled to the frame 106 by any suitable connection system, such as a welded connection, fasteners, an adhesive connection, another suitable connection system, or a combination thereof. The front axle assembly 108 is configured to support a front left wheel 112 and a front right wheel, and the rear axle assembly 110 is configured to support a rear left wheel 114 and a rear right wheel. While each axle assembly is configured to support wheels in the illustrated embodiment, in other embodiments, at least one axle assembly may be configured to support tracks.
[0018] In the illustrated embodiment, the agricultural harvester 100 also includes a blower 116 and an auger assembly 118. The blower 116 and the auger assembly 118 are coupled to the frame 106, such that the frame 106 supports the blower 116 and the auger assembly 118. The blower 116 and the auger assembly 118 may be coupled to the frame 106 by any suitable connection system, such as a welded connection, fasteners, an adhesive connection, another suitable connection system, or a combination thereof. As previously discussed, the blower 116 is configured to provide an airflow that conveys harvested agricultural product to the auger assembly 118. The auger assembly 118, in turn, is configured to receive the agricultural product and to convey the agricultural product outwardly (e.g., along a lateral axis 18) toward outlets 120 of the auger assembly 118 (e.g., via rotation of an auger of the

auger assembly). An outlet tube coupled to each outlet 120 is configured to enable the agricultural product to flow to a respective elevator. Each elevator, in turn, is configured to move the agricultural product upwardly (e.g., along a vertical axis 20) toward an internal storage compartment of the agricultural harvester. While the illustrated auger assembly 118 includes two outlets 120 configured to facilitate passage of the agricultural product to two respective elevators, in other embodiments, the auger assembly may have more or fewer outlets, such as 1, 2, 3, 4, 5, 6, or more outlets (e.g., each coupled to a respective elevator).
[0019] In the illustrated embodiment, the front axle assembly 108 has an input configured to receive rotational energy. The front axle assembly 108 also has output shafts coupled to the input and configured to transfer the rotational energy from the input to the front wheels. In addition, the agricultural harvester 100 includes a transmission 122 configured to receive rotational energy from an engine and to output the rotational energy to the input of the front axle assembly 108. For example, the engine may be coupled to an input shaft of the transmission, and an output shaft of the transmission may be coupled to the input of the front axle assembly. The transmission 122 (e.g., power shift transmission, continuously variable transmission, automatic transmission, etc.) is configured to control the speed of the output shaft relative to the input shaft by changing gear ratios. Accordingly, the rotational speed of the front wheels may be controlled by varying the speed of the engine and/or varying the gear ratio of the transmission.
[0020] In the illustrated embodiment, the four wheel drive system 200 includes an input shaft 202 configured to receive rotational energy from the transmission 122. In certain embodiments, the transmission 122 has an intermediate shaft, which may be coupled to the transmission input shaft and to the transmission output shaft via respective gear pairs. In such embodiments, the input shaft 202 of the four wheel drive system 200 may be coupled to the intermediate shaft of the transmission 122 to facilitate rotational energy transfer from the transmission 122 to the four wheel drive system 200. However, in other embodiments, the input shaft of the four wheel drive system may be coupled to any other suitable rotating component of the transmission (e.g., the input shaft, the output shaft, a second intermediate shaft, etc.). Furthermore,

in certain embodiments, the input shaft of the four wheel drive system may be coupled to another suitable rotating component, such as an output of the engine, an output shaft of the front axle assembly, among other suitable rotating components. In the illustrated embodiment, the input shaft 202 extends outwardly from the transmission 122 along the lateral axis 18. However, in alternative embodiments, the input shaft 202 may be angled relative to the lateral axis 18.
[0021] In the illustrated embodiment, the four wheel drive system 200 includes a gearbox 204, separate from the transmission 122. The gearbox 204 has an input coupled to the input shaft 202 and an output coupled to a drive shaft assembly 206 of the four wheel drive system 200. In the illustrated embodiment, the output of the gearbox 204 is substantially perpendicular to the input of the gearbox 204, thereby enabling the drive shaft assembly 206 to extend substantially along the longitudinal axis 16. In certain embodiments, the gearbox includes bevel gears configured to transfer rotational energy from the input shaft to the drive shaft assembly. However, in alternative embodiments, the gearbox may include any other suitable gear assembly (e.g., to transfer rotational energy from an input to an output substantially perpendicular to the input). While the gearbox output is substantially perpendicular to the gearbox input in the illustrated embodiment, in other embodiments, the gearbox output may be oriented at any suitable angle relative to the gearbox input. Furthermore, while the gearbox transfers rotational energy from the input shaft to the drive shaft assembly in the illustrated embodiment, in other embodiments, another suitable system, such as a flexible drive cable, may be utilized to transfer rotational energy from the input shaft to the drive shaft assembly. In further embodiments, the drive shaft assembly may be coupled to the transmission, the front axle assembly, or another suitable rotating component of the agricultural harvester by another system/assembly suitable for transferring rotational energy to the drive shaft assembly.
[0022] As illustrated, the drive shaft assembly 206 extends substantially along the longitudinal axis 16 of the agricultural harvester 100. In the illustrated embodiment, the drive shaft assembly 206 includes a first drive shaft 208 coupled to the gearbox 204 (e.g., the output of the gearbox), a first joint 210 (e.g., universal joint) coupled to

the first drive shaft 208, a second drive shaft 212 coupled to the first joint 210, a second joint 214 (e.g., universal joint) coupled to the second drive shaft 212, and a third drive shaft 216 coupled to the second joint 214 and to the rear axle assembly 110 (e.g., an input of the rear axle assembly). In the illustrated embodiment, the third drive shaft 216 is a telescoping drive shaft (e.g., having an inner shaft and an outer shaft configured to translate relative to one another while remaining non-rotatably coupled to one another). The telescoping drive shaft facilitates installation of the drive shaft assembly within the agricultural harvester and/or facilitates movement of the rear axle assembly (e.g., rotation about the longitudinal axis) during operation of the agricultural harvester. While the third drive shaft is a telescoping drive shaft in the illustrated embodiment, in other embodiments, the third drive shaft may be a non-telescoping drive shaft and/or at least one of the first and second drive shafts may be a telescoping drive shaft.
[0023] While the illustrated drive shaft assembly includes three drive shafts, in other embodiments, the drive shaft assembly may include more or fewer drive shafts and corresponding joints positioned between the drive shafts. In the illustrated embodiment, the first drive shaft 208 is coupled to the output of the gearbox 204 by a third joint 218, and the third drive shaft 216 is coupled to an input 124 of the rear axle assembly 110 by a fourth joint 220. The joints enable the drive shafts to move relative to one another and relative to the gearbox/rear axle assembly. The drive shaft assembly 206 is configured to transfer rotational energy (e.g., power) from the gearbox 204 to the rear axle assembly 110, thereby driving the rear wheels to rotate (e.g., via output shafts of the rear axle assembly, which may be coupled to the input of the rear axle assembly).
[0024] In certain embodiments, a clutch may be disposed between the transmission 122 and the rear axle assembly 110 to control rotation of the rear wheels. For example, the clutch may be positioned between the transmission 122 and the input shaft 202, between the input shaft 202 and the gearbox 204, between the gearbox 204 and the drive shaft assembly 206, between the drive shaft assembly 206 and the rear axle assembly 110, or between drive shafts of the drive shaft assembly 206. The clutch may be engaged to drive the rear wheels to rotate (e.g., during periods of lower

traction, such as when the agricultural harvester is operating within a region having softer soil), and the clutch may be disengaged to terminate rotational energy transfer to the rear wheels (e.g., during periods of greater traction, such as when the agricultural harvester is operating within a region having firmer soil). In certain embodiments, the clutch may be omitted, such that the rear wheels are driven regardless of soil conditions.
[0025] In the illustrated embodiment, at least a portion of the second drive shaft 212 extends within a vertical extent and a longitudinal extent of the auger assembly 118 (e.g., the extent of the auger assembly 118 along the vertical axis 20, and the extent of the auger assembly 118 along the longitudinal axis 16), such that the portion of the second drive shaft 212 and the auger assembly 118 overlap one another along the vertical axis 20 and along the longitudinal axis 16. Furthermore, the second drive shaft 212 is positioned laterally outward of the auger assembly 118 (e.g., outward of the auger assembly outlets 120 along the lateral axis 18). In addition, the second drive shaft 212 is positioned beneath (e.g., beneath the elevator(s) along the vertical axis 20) or laterally inward of the elevator(s) (e.g., inward of the elevator(s) along the lateral axis 18). Accordingly, in certain embodiments, the second drive shaft 212 is positioned between the outlets 120 of the auger assembly 118 and the elevator(s) along the lateral axis 18. By positioning the second drive shaft 212 laterally outward from the auger assembly 118, the minimum distance between the drive shaft assembly 206 and the soil surface along the vertical axis 20 may be greater than the minimum distance between the soil surface and a drive shaft assembly that extends under the auger assembly, thereby increasing the ground clearance of the agricultural harvester 100.
[0026] The outlets 120 of the auger assembly 118 are formed within an end plate 126 of the auger assembly 118. In certain embodiments, the end plate 126 is directly coupled to the frame 106 of the agricultural harvester (e.g., by a welded connection, by fasteners, etc.). In the illustrated embodiment, the agricultural harvester 100 includes a support member 127 coupled to the end plate 126 of the auger assembly 118 (e.g., via a welded connection, via fasteners, etc.), and the support member 127 is configured to rotatably support the second drive shaft 212. In certain embodiments,

one or more bearings may be coupled to the support member 127, and the second drive shaft 212 may extend through the bearings. The bearings may facilitate rotation of the second drive shaft 212, and the support member 127 may be coupled to the second drive shaft 212 via the bearings. Because the support member 127 is coupled to the end plate 126, and because the end plate 126 is coupled (e.g., directly coupled) to the frame 106 of the agricultural harvester 100, the end plate 126 and the support member 127 are configured to support the drive shaft assembly 206 on the frame 106 of the agricultural harvester 100.
[0027] In the illustrated embodiment, the drive shaft assembly 206 is also coupled to the frame 106 of the agricultural harvester 100 by the gearbox 204 and the rear axle assembly 110. As illustrated, the gearbox 204 is coupled to the frame 106 by a bracket 128. Accordingly, a first end of the drive shaft assembly 206 is supported on the frame 106 by the bracket 128 and the gearbox 204. In addition, the rear axle assembly 110 is coupled to the frame 106 by a mounting assembly 130. In certain embodiments, the rear axle assembly 110 is coupled to the mounting assembly 130 by a pivot joint that enables the rear axle assembly 110 to rotate about the longitudinal axis 16 relative to the frame 106 during operation of the agricultural harvester 100. A second end of the drive shaft assembly 206 is supported on the frame 106 by the mounting assembly 130 and the rear axle assembly 110. While the drive shaft assembly 206 is supported by the gearbox 204/bracket 128, the rear axle assembly 110/mounting assembly 130, and the end plate 126/support member 127 in the illustrated embodiment, in other embodiments, the drive shaft assembly may be support by other and/or additional suitable mounting devices/systems.
[0028] As previously discussed, the rear axle assembly 110 is configured to support the left wheel 114 on the left side of the rear axle assembly 110 and to support the right wheel on the right side of the rear axle assembly 110. In the illustrated embodiment, the input 124 of the rear axle assembly 110 is laterally offset from a midpoint between the left wheel 114 and the right wheel (e.g., the input 124 is offset from a longitudinal centerline 22 of the agricultural harvester 100). As illustrated, the input 124 of the rear axle assembly 110 is positioned on a right side 24 of the agricultural harvester 100. In addition, the gearbox 204 is positioned on the right side

24 of the agricultural harvester (e.g., due to the input shaft 202 extending laterally outward from the transmission 122 toward the right side 24 of the agricultural harvester 100). In the illustrated embodiment, the gearbox 204 and the input 124 of the rear axle assembly 110 are substantially aligned with one another along the lateral axis 18. Accordingly, the drive shaft assembly 206 extends substantially along (e.g., parallel to) the longitudinal axis 16 of the agricultural harvester 100.
[0029] While the drive shaft assembly 206 extends substantially along the longitudinal axis 16 in the illustrated embodiment, in other embodiments, the drive shaft assembly may follow another suitable path between the gearbox and the input of the rear axle assembly. For example, in certain embodiments, the first drive shaft may be angled relative to the longitudinal axis to connect a gearbox positioned laterally inward of the illustrated gearbox to the second drive shaft (e.g., which may be longer or shorter than the illustrated second drive shaft). In addition, the third drive shaft may be angled relative to the longitudinal axis to connect a rear axle assembly input positioned laterally inward of the illustrated rear axle assembly input to the second drive shaft (e.g., which may be longer or shorter than the illustrated second drive shaft). In such embodiments, the second drive shaft may be positioned laterally outward of the auger assembly to enable the drive shaft assembly to be positioned higher than a drive shaft assembly extending beneath the auger assembly, thereby increasing the ground clearance of the agricultural harvester.
[0030] While the drive shaft 206 assembly is positioned on the right side 24 of the agricultural harvester 100 in the illustrated embodiment, in other embodiments, the drive shaft assembly may be positioned on a left side 26 of the agricultural harvester (e.g., on an opposite side of the longitudinal centerline 22 from the illustrated drive shaft assembly). In such embodiments, the gearbox and the rear axle input may also be positioned on the left side of the agricultural harvester. In certain embodiments, the elevator(s) may be positioned on the left side of the agricultural harvester. In such embodiments, the second drive shaft may be positioned between the outlet(s) of the auger assembly and the elevator(s) or beneath the elevator(s). However, in other embodiments, the elevator(s) may be positioned on the right side of the agricultural harvester, as illustrated. In such embodiments, the second drive shaft may be

positioned laterally outward of the auger assembly (e.g., outward of the auger assembly along the lateral axis) and remote from the elevator(s) (e.g., on an opposite side of the longitudinal axis from the elevator(s)).
[0031] Furthermore, while the second drive shaft 212 is positioned laterally outward of the auger assembly 118 at the longitudinal position of the auger assembly in the illustrated embodiment, in other embodiments, another portion of the drive shaft assembly may be positioned laterally outward of the auger assembly at the longitudinal position of the auger assembly. For example, the first drive shaft, the second drive shaft, the third drive shaft, or any combination thereof may be positioned laterally outward of the auger assembly at the longitudinal position of the auger assembly (e.g., depending on the length, position, and orientation of each drive shaft). In addition, while the transmission transfers rotational energy to the front axle assembly in the illustrated embodiment, in other embodiments, the transmission may transfer rotational energy to the rear axle assembly. In such embodiments, the drive shaft assembly may transfer rotational energy from the transmission (e.g., from an intermediate shaft of the transmission) to the front axle assembly (e.g., while the agricultural harvester is operating within a region having soft soil).
[0032] FIG. 2B is a right side view of the four wheel drive system 200 of FIG. 2A. As previously discussed, the drive shaft assembly extends substantially along (e.g., parallel to) the longitudinal axis 16 between the gearbox 204 and the input 124 of the rear axle assembly 110. As illustrated, at least a portion of the second drive shaft 212 of the drive shaft assembly 206 extends within a longitudinal extent of the auger assembly 118 (e.g., the extent of the auger assembly 118 along the longitudinal axis 16), such that the portion of the second drive shaft 212 and the auger assembly 118 overlap one another along the longitudinal axis 16. In addition, the second drive shaft 212 is positioned between the auger assembly 118 and the elevators 132. In the illustrated embodiment, at least a portion of the second drive shaft 212 extends within a vertical extent of the elevators 132 (e.g., the extent of the elevators 132 along the vertical axis 20), such that the portion of the second drive shaft 212 and the elevators 132 overlap one another along the vertical axis 20. For example, a portion of the second drive shaft may extend within the vertical extent of the elevator(s) and the

longitudinal extent of the auger assembly, such that the portion of the second drive shaft and the elevator(s) overlap one another along the vertical axis, and the portion of the second drive shaft and the auger assembly overlap one another along the longitudinal axis. Because the second drive shaft 212 is positioned between the auger assembly 118 and the elevators 132, a minimum distance 28 (e.g., ground clearance) between the drive shaft assembly 206 and the surface 10 of the agricultural field 12 may be greater than the minimum distance between the field surface and a drive shaft assembly extending beneath the auger. For example, the ground clearance 28 may be about 300 mm to about 600 mm, about 400 mm to about 500 mm, or about 440 mm to about 480 mm. The increased ground clearance may enable the agricultural harvester to traverse larger obstacles within the agricultural field 12.
[0033] While the second drive shaft is positioned between the auger assembly and the elevators in the illustrated embodiment, in other embodiments, another suitable portion of the drive shaft assembly may be disposed between the auger assembly and the elevators at the longitudinal position of the auger assembly and/or the elevators. Furthermore, in certain embodiments, the second drive shaft, or another suitable portion of the drive shaft assembly, may be positioned below the elevators (e.g., in embodiments in which the elevators are positioned higher than the illustrated elevators). In addition, in certain embodiments, the drive shaft assembly may be positioned on an opposite side of the longitudinal centerline from the elevators. In such embodiments, a portion of the drive shaft assembly (e.g., a portion of the second drive shaft) may also overlap the elevators along the vertical axis.
[0034] FIG. 2C is a top view of the four wheel drive system 200 of FIG. 2A. As illustrated, the second drive shaft 212 is positioned between the auger assembly 118 and the elevators 132 along the lateral axis 18. In the illustrated embodiment, a tube 134 is configured to enable the agricultural product to flow from the auger assembly 118 to each elevator 132. As illustrated, each tube 134 extends along the lateral axis 18 from a respective outlet of the auger assembly 118 to the respective elevator 132. As discussed in detail below, the second drive shaft 212 is positioned below each tube 134 along the vertical axis. In certain embodiments, each tube may be considered an

element of a respective elevator. In such embodiments, the second drive shaft may be positioned beneath the elevators along the vertical axis.
[0035] As previously discussed, the rear axle assembly 110 is configured to support the left wheel on the left side of the rear axle assembly 110 and to support the right wheel on the right side of the rear axle assembly 110. In the illustrated embodiment, the input 124 of the rear axle assembly 110 is laterally offset from a midpoint between the left wheel 114 and the right wheel (e.g., the input 124 is offset from the longitudinal centerline 22 of the agricultural harvester 100). As illustrated, the input 124 of the rear axle assembly 110 is positioned on the right side 24 of the agricultural harvester 100. In addition, the gearbox 204 is positioned on the right side 24 of the agricultural harvester (e.g., due to the input shaft 202 extending laterally outward from the transmission 122 toward the right side 24 of the agricultural harvester 100). In the illustrated embodiment, the gearbox 204 and the input 124 of the rear axle assembly 110 are substantially aligned with one another along the lateral axis 18. Accordingly, the drive shaft assembly 206 extends substantially along (e.g., parallel to) the longitudinal axis 16 of the agricultural harvester 100.
[0036] FIG. 2D is a back view of a portion of the four wheel drive system 200 of FIG. 2A. As illustrated, the second drive shaft 212 is positioned laterally outward of the auger assembly 118 (e.g., outward of the auger assembly along the lateral axis 18) and laterally inward of the elevators 132 (e.g., inward of the elevators 132 along the lateral axis 18), such that the second drive shaft 212 is positioned between the auger assembly 118 and the elevators 132 along the lateral axis 18. In addition, a portion of the second drive shaft 212 extends within a vertical extent of the auger assembly 118 (e.g., the extent of the auger assembly along the vertical axis 20), such that the portion of the second drive shaft 212 and the auger assembly 118 overlap one another along the vertical axis 20. Furthermore, the second drive shaft 212 is positioned beneath each tube 134 along the vertical axis 20.
[0037] In the illustrated embodiment, each tube 134 extends from the end plate 126 of the auger assembly 118 to an inner wall 140 of a respective elevator 132. As illustrated, the second drive shaft 212 is positioned directly below each tube 134 along

the vertical axis 20, and between the end plate 126 of the auger assembly 118 and the inner wall 140 of the laterally inward elevator 132 along the lateral axis 18. Accordingly, the maximum width (e.g., diameter) of the second drive shaft 212 is less than the distance between the auger assembly 118 (e.g., the end plate 126 of the auger assembly 118) and the laterally inward elevator 132 (e.g., the inner wall 140 of the laterally inward elevator 132). In addition, a portion of the second drive shaft 212 extends within a vertical extent of the inner walls 140 of the elevators 132 (e.g., the extent of the inner walls 140 along the vertical axis 20), such that the portion of the second drive shaft 212 and the inner walls overlap one another along the vertical axis 20. In alternative embodiments, the second drive shaft, or the portion of the drive shaft assembly positioned laterally outward of the auger assembly at the longitudinal position of the auger assembly, may be positioned directly beneath an elevator (e.g., the inner wall of the elevator), among other suitable locations.
[0038] FIG. 3 is a perspective view of another embodiment of a four wheel drive system 300 that may be employed within the agricultural harvester of FIG. 1. In the illustrated embodiment, the four wheel drive system 300 includes an input shaft 302 configured to receive rotational energy from the transmission 122. The four wheel drive system 300 also includes a gearbox 304, separate from the transmission 122. The gearbox 304 has an input coupled to the input shaft 302 and an output coupled to a drive shaft assembly 306 of the four wheel drive system 300. In the illustrated embodiment, the drive shaft assembly 306 includes a first drive shaft 308 coupled to the gearbox 304 (e.g., the output of the gearbox), a first joint 310 (e.g., universal joint) coupled to the first drive shaft 308, and a second drive shaft 312 coupled to the first joint 310 and to the input 124 of the rear axle assembly 110. Furthermore, in the illustrated embodiment, the second drive shaft 312 is a telescoping drive shaft (e.g., having an inner shaft and an outer shaft configured to translate relative to one another while remaining non-rotatably coupled to one another). The telescoping drive shaft facilitates installation of the drive shaft assembly within the agricultural harvester and/or facilitates movement of the rear axle assembly (e.g., rotation about the longitudinal axis) during operation of the agricultural harvester. While the second drive shaft is a telescoping drive shaft in the illustrated embodiment, in other

embodiments, the second drive shaft may be a non-telescoping drive shaft and/or the first drive shaft may be a telescoping drive shaft.
[0039] While the illustrated drive shaft assembly includes two drive shafts, in other embodiments, the drive shaft assembly may include more or fewer drive shafts and corresponding joints positioned between the drive shafts. In the illustrated embodiment, the first drive shaft 308 is coupled to the output of the gearbox 304 by a second joint 314, and the second drive shaft 312 is coupled to the input 124 of the rear axle assembly 110 by a third joint 316. The joints enable the drive shafts to move relative to one another and relative to the gearbox/rear axle assembly. The drive shaft assembly 306 is configured to transfer rotational energy (e.g., power) from the gearbox 304 to the rear axle assembly 110, thereby driving the rear wheels to rotate.
[0040] In the illustrated embodiment, a portion of the first drive shaft 308 extends within a longitudinal extent of the auger assembly 118 (e.g., the extent of the auger assembly 118 along the longitudinal axis 16), such that the portion of the first drive shaft 308 and the auger assembly 118 overlap one another along the longitudinal axis 16. Furthermore, the first drive shaft 308 is positioned laterally outward of the auger assembly 118 (e.g., outward of the auger assembly outlets along the lateral axis 18). In addition, the first drive shaft 308 is positioned beneath the elevator(s) (e.g., beneath the elevator(s) along the vertical axis 20) or laterally inward of the elevator(s) (e.g., inward of the elevator(s) along the lateral axis 18). Accordingly, in certain embodiments, the first drive shaft 308 is positioned between the auger assembly 118 and the elevator(s) along the lateral axis 18. By positioning the first drive shaft 308 laterally outward of the auger assembly 118, the minimum distance between the drive shaft assembly 306 and the soil surface along the vertical axis 20 may be greater than the minimum distance between the soil surface and a drive shaft assembly that extends under the auger assembly, thereby increasing the ground clearance of the agricultural harvester 100.
[0041] While only certain features have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be

understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure.
[0042] The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function]…” or “step for [perform]ing [a function]…”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).

CLAIMS:
1.An agricultural harvester, comprising:
an auger assembly configured to move agricultural product toward an elevator;
a drive shaft assembly, wherein a portion of the drive shaft assembly is positioned laterally outward of the auger assembly, and the portion of the drive shaft assembly extends within a vertical extent and a longitudinal extent of the auger assembly, such that the portion of the drive shaft assembly and the auger assembly overlap one another along a vertical axis and along a longitudinal axis of the agricultural harvester; and
an axle assembly having an input, wherein the drive shaft assembly is coupled to the input of the axle assembly, and the drive shaft assembly is configured to transfer rotational energy.
2.The agricultural harvester of claim 1, comprising the elevator, wherein the elevator is configured to receive the agricultural product from an outlet of the auger assembly, and the portion of the drive shaft assembly is positioned beneath or laterally inward of the elevator.
3.The agricultural harvester of claim 1, wherein the axle assembly is configured to support a left wheel on a left side of the axle assembly and to support a right wheel on a right side of the axle assembly, and the input of the axle assembly is laterally offset from a midpoint between the left wheel and the right wheel.
4.The agricultural harvester of claim 1, wherein the drive shaft assembly comprises a first drive shaft, a second drive shaft coupled to the input of the axle assembly, and a joint coupling the first drive shaft to the second drive shaft.
5.The agricultural harvester of claim 1, wherein the drive shaft assembly comprises a first drive shaft, a first joint coupled to the first drive shaft, a second drive shaft coupled to the first joint, a second joint coupled to the second drive shaft, and a third drive shaft coupled to the second joint and to the input of the axle assembly.
6.The agricultural harvester of claim 5, comprising a support member, wherein an outlet of the auger assembly is formed within an end plate of the auger assembly, the support member is coupled to the end plate of the auger assembly, and the support member is configured to rotatably support the second drive shaft.
7.The agricultural harvester of claim 1, comprising a gearbox coupled to the drive shaft assembly and configured to drive the drive shaft assembly to rotate.
8.The agricultural harvester of claim 7, comprises a transmission, wherein an intermediate shaft of the transmission is coupled to the gearbox, and the gearbox is configured to transfer the rotational energy from the intermediate shaft of the transmission to the drive shaft assembly.
9.An agricultural harvester, comprising:
an auger assembly configured to move agricultural product toward an outlet;
an elevator configured to receive the agricultural product from the outlet of the auger assembly;
a drive shaft assembly, wherein a portion of the drive shaft assembly extends within a longitudinal extent of the auger assembly, such that the portion of the drive shaft assembly and the auger assembly overlap one another along a longitudinal axis of the agricultural harvester, and wherein the portion of the drive shaft assembly is positioned between the outlet of the auger assembly and the elevator along a lateral axis of the agricultural harvester; and
an axle assembly having an input, wherein the drive shaft assembly is coupled to the input of the axle assembly, and the drive shaft assembly is configured to transfer rotational energy.
10.The agricultural harvester of claim 9, wherein the axle assembly is
configured to support a left wheel on a left side of the axle assembly and to support a
right wheel on a right side of the axle assembly, and the input of the axle assembly is
laterally offset from a midpoint between the left wheel and the right wheel.
11.The agricultural harvester of claim 9, wherein the portion of the drive shaft assembly extends within a vertical extent of the elevator, such that the portion of the drive shaft assembly and the elevator overlap one another along a vertical axis of the agricultural harvester.
12.The agricultural harvester of claim 9, comprising a gearbox coupled to the drive shaft assembly and configured to drive the drive shaft assembly to rotate.
13.The agricultural harvester of claim 12, comprises a transmission, wherein an intermediate shaft of the transmission is coupled to the gearbox, and the gearbox is configured to transfer the rotational energy from the intermediate shaft of the transmission to the drive shaft assembly.
14.The agricultural harvester of claim 9, whereinz the drive shaft assembly comprises a first drive shaft, a first joint coupled to the first drive shaft, a second drive shaft coupled to the first joint, a second joint coupled to the second drive shaft, and a third drive shaft coupled to the second joint and to the input of the axle assembly.
15.The agricultural harvester of claim 14, comprising a support member,
wherein the outlet of the auger assembly is formed within an end plate of the auger
assembly, the support member is coupled to the end plate of the auger assembly, and
the support member is configured to rotatably support the second drive shaft.
16.The agricultural harvester of claim 9, wherein the drive shaft assembly comprises a first drive shaft, a second drive shaft coupled to the input of the axle assembly, and a joint coupling the first drive shaft to the second drive shaft.
17.An agricultural harvester, comprising:
a transmission configured to receive rotational energy from an engine of the agricultural harvester, wherein the transmission comprises an intermediate shaft;
an input shaft coupled to the intermediate shaft and extending outwardly from the intermediate shaft substantially along a lateral axis of the agricultural harvester;
a gearbox having an input and an output, wherein the input is coupled to the input shaft, and the output is substantially perpendicular to the input;
a drive shaft assembly coupled to the output of the gearbox and extending substantially along a longitudinal axis of the agricultural harvester;
an axle assembly configured to support a left wheel on a left side of the axle assembly and to support a right wheel on a right side of the axle assembly, wherein the axle assembly has an input laterally offset from a midpoint between the left wheel and the right wheel, and the drive shaft assembly is coupled to the input of the axle assembly; and
an auger assembly configured to move agricultural product toward an elevator;
wherein a portion of the drive shaft assembly extends within a longitudinal extent of the auger assembly, such that the portion of the drive shaft assembly and the auger assembly overlap one another along the longitudinal axis, and wherein the portion of the drive shaft assembly is positioned outward of the auger assembly along the lateral axis.
18.The agricultural harvester of claim 17, wherein the portion of the drive shaft assembly extends within a vertical extent of the auger assembly, such that the portion of the drive shaft assembly and the auger assembly overlap one another along a vertical axis of the agricultural harvester.
19.The agricultural harvester of claim 17, wherein the drive shaft assembly comprises a first drive shaft coupled to the output of the gearbox, a first joint coupled to the first drive shaft, a second drive shaft coupled to the first joint, a second joint coupled to the second drive shaft, and a third drive shaft coupled to the second joint and to the input of the axle assembly.
20 The agricultural harvester of claim 17, comprising the elevator, wherein the elevator is configured to receive the agricultural product from an outlet of the auger assembly, and the portion of the drive shaft assembly is positioned beneath the elevator or inward of the elevator along the lateral axis.